Cleaning slab for continuous furnaces



Oct. 11, 1938.

J. w. WElSEN CLEANING SLAB FOR CONTINUOUS FURNACES Filed Sept. 20, 19572 Sheets-Sheet 1 JOSEPH W Wig/55M,

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Oct. 11, 1938. J w. w N 2,132,591

CLEANING SLAB FOR CONTINUOU FURNACES Filed Sept. 20, 1937 2Sheets-Sheet. 2

mom/ r JOSEPH /1 M's/557v,

Patented Oct. 11, 1938 PATENT OFFICE CLEANING SLAB FOR CONTINUOUS.

FURNACES Joseph W. Weisen, Pittsburgh, Pa.

' Application September 20, 1937, Serial No. 164,783

9 Claims.

This invention relates to continuous reheating furnaces and,particularly, to an improved device for use in cleaning the hearth ofsame.

' As steel slabs, blooms, or billets are reheated in a continuousfurnace for rolling they tend to lose part of their scale as they passtherethrough. This scale tends to melt and accumulate on the hearth ofthe furnace, thus necessitating frequent cleaning or scraping of thesame. If this deposit in is not cleaned from the hearth, it will tend tocause coldspots in the metal as it passes thereover which is, of course,very undesirable.

Heretofore, it has usually been the practice to shut down the furnaceand to lift each slab, billet or bloom ofi the hearth and support it bymeans of steel blocks or some other suitablev means while the hearth wasscraped and thoroughly cleaned of the accumulation of cinder and scale.This was very disagreeable and tedious and was usual- 1y done while thefurnace was still hot in order to save time. Due to the diflicultyexperienced in cleaning, the hearths were not thoroughly cleaned 1:01cleaned as frequently as they should have een.

It is, therefore, an object of this invention to provide a means wherebythe hearth of continuous reheating furnaces can be easily and quicklycleaned without having to-shut down the furnace.

It is also another object of this invention to provide a cleaning memberadapted for use in continuous reheating furnaces whichwill tend toautomatically clean the hearth as it passes thereover.

It is a further object of this inventionto provide a cleaning memberwhich will permit free access to the bottom of the hearth for cleaningthesame as it passes thereover while the furnace is in continuousoperation.

Various other objects and advantages of my invention will more fullyappear during the course of the following specification and will be moreparticularly pointed out in the appended claims.

In the accompanying drawings I have shown, for the purpose ofillustration, one embodiment which my invention may assume in practice.

1 In the drawings:

50 Figure 1 is a longitudinal sectional view through a continuousreheating furnace showing the improved cleanout slab of my inventionpassing therethrough.

Figure 2 is a sectional view on the line lI-II 55 of Figure 1, showing adouble row of slabs.

Figure 3 is a plan view of my improved cleanout slab.

Figure 4 is a side elevation thereof.

Figure 5 is an end view thereof.

Continuous reheating furnaces are usually charged through a door at oneend thereof and the steel slabs, billets or blooms fed into and movedcontinuously therethrough by some suitable means, and discharged at theopposite end. In the continuous furnace shown in the accompanyingdrawings, the steel slabs 5 are successively placed in side-by-siderelation on the entry roller-table 6 at the charging end of the furnaceand fed over the skids l, and into the furnace through the opening 8, bymeans of the mechanical pusher 9, and as each successive slab is chargedthe slabs that have been previously charged gradually move through theheatedfurnace, over the hearth l0, down the slide II, and out throughthe discharge door l2.

According to the present invention, there is provided a longitudinallyextending slab-like cleaning member l3 of a U-shapcd cross-sectionhaving a channel, andflanges l5. 1 This member may becast or fabricated,and preferably has ribs I" to strengthen it so as it will not warp afterit has been heated and cooled each time it is used, and can be used foran indefinite number of cleanings.

The flanges or free edges 15 of the member are preferably relievedoutwardly as at l5, and have concave or inwardly inclined inner surfacesI'I, so as to form sharp, longitudinally extending, toe-like orplow-like edges 3. It is important that the thickness of the member onall sections, that is, the solid cross-section of the member, be atleast equal to, or preferably greater than, the cross-section of themetal slabs or articles to be heated. If this cleaning member is not ofsuflicient thickness, that is, smaller than the metal articles to beheated, it will tend to melt away and lose its shape and be of no usewhatsoever.

Whenever it is desired to clean the hearth surface of the furnace, thisU-shaped cleaning slab is placed on the entry table in the charging linein the inverted portion with its flanges extending downwardly just asone of the slabs is placed therein and, likewise, moved through thefurnace.

' When the cleaning slab reaches the hearth the doors on the openings 19on the side of the furnace are opened and each of the successive areasof the hearth, presented to and enclosed by the channel ll of themember, scraped and thoroughly cleaned as the cleaning slab graduallypasses from one end thereof to the other. That is, the working area orthe area to be cleaned gradually moves forward as the cleaning slabmoves over the hearth and as the slabs advance through the furnace.Finally; when the cleaning slab reaches the end of the hearth, it slidesdown the skids l I and out of the furnace in the same manner as theordinary slabs and is laid aside and allowed to cool for the nextcleaning.

As the cleaning slab passes over the hearth, the sharp inner toe-like orplow-like edges l8 of one of the flanges is adapted to scrape thesurface thereof to loosen the accumulated slag or cinders therefromwhich can be either removed through the side openings IE or carriedalongby the cleaning slab and out of the furnace therewith.

As a result of my invention, it will-be noted that I have provided aninexpensive cleaning member for use in cleaning continuous reheatingfurnaces which is easy to use and effective in its operation, therebyencouraging its use and resulting in the production of better productsand the extension of the lives of the furnaces.

While I have shown and described a specific embodiment of my invention,it will be understood that this is merely for the purpose ofillustration and description, and that various other modifications maybe devised within the scope of the invention, as defined in the appendedclaims.

I claim:

1. The method of cleaning the hearth of a continuous furnace for heating'steel slabs which comprises charging the furnace at one end with steelslabs, feeding and moving said slabs into and through said furnace,periodically placing a channel-like flanged metal cleaning member in thecharging line with the flanges thereof extending downwardly and movingthe same through the furnace, and cleaning the hearth in under thechannel portion of said member from openings in the side of the furnaceas said member passes thereover.

2. The method of cleaning the hearth of a continuous furnace for heatingsteel slabs which comprises charging the furnace at one end with steelslabs, feeding and moving said slabs into and through said furnace,periodically placing a channel-like flanged metal cleaning member in thecharging line with the flanges thereof extending downwardly and movingthe same through the furnace, and cleaning the entire hearth surfacefrom openings in the side of the furnace by cleaning the successiveareas of the hearth enclosed by the channel member as it passesthereover.

3. The method of cleaning the hearth of a continuous furnace for heatingsteel slabs which comprises charging the furnace at one end with 4. Acleaning slab for use in continuous furnaces for heating metal slabs andthe like, comprising a longitudinally extending metal member having .aninverted U-shaped cross-section and adapted to be moved over the furnacehearth 1 with the articles to be heated, said member having a solidcross-section at least as great as the cross-section of the metalarticles to be heated, the free ends of the legs of said member beingrelieved outwardly and the inner vertical faces of 2 said legs beingconcave so as to form sharp plowlike cutting and scraping edges.

5. A metallic slab for cleaning continuous fur- 4 naces for heatingmetal slabs and the like comprising a longitudinally extending memberhav- 2 ing an inverted U-shaped cross-section.

6. A metallic slab member for cleaning continuous furnaces for heatingmetal'slabs and the like comprising a longitudinally extending member ofinverted U-shaped cross-section, said mem- I ber having at least one ofits flanges provided with a sharp scraping edge.

7. A metallic slab for cleaning continuous furnaces for heating metalslabs comprising an inverted channel-like longitudinally extendingslablike member having inner sharp edged longitudinally extendingflanges which are adapted to clean the hearth as the cleaning slabpasses thereover.

8, A metallic slab for cleaning continuous furnaces for heating metalslabs and the like comprising a longitudinally extending metal memberhaving an inverted U-shaped cross-section, said cleaning slab adapted tobe placed in the furnace in its inverted position and to be moved overthe hearth with the slabs to be heated to clean the same.

9. A metallic slab for cleaning continuous furnaces for heating metalslabs and the like comprising a longitudinally extending metal memberhaving an inverted U-shaped cross-section, and being at least as thickas the metal slabs to be heated, said cleaning slab adapted to be placedin the hearth of the furnace in its inverted position and movedthereover with the slabs to be I heated to clean the same.

JOSEPH W. W'ElZSEN.

